Optical recording devices

Another type of instrument that has been made possible by the availability of lasers is known as the time-of-flight instrument. Here, a narrow focused beam of laser light explores an area of a suspension. The size of the particles in suspension is measured by the time it takes for a laser beam to pass across the profile of the fine particle. Sophisticated optical recording devices and electronic editors are used to generate the size distribution data from the information generated by the device. 

For practical applications in optical recording devices, photochromic molecules must satisfy the following requirements ... 

NLO materials find use in optical recording devices. To improve resolution, it is desirable to use higher frequency light. Frequency multiplication with NLO provides a means by which higher frequency light can be obtained from a laser. 

Early investigations on this polymer employed it in the formation of graphite intercalation complexes with, for example, potassium and FeQa. High conductivities were observed in these materials ( > 10 S/cm). More recently, however, PPV and its derivatives have been of interest for their third-order nonlinear optical properties, and in optical recording devices. PPV has also found application as a li t-emitting diode. ... 

S. Kaneko, Solid-State Image Sensor Masakiyo Matsumura, Charge-Coupled Devices M.A. Bosch, Optical Recording... 

P. G. LeComber and W. E. Spear, The Development of the a-Si H Field-Effect Transistor and Its Possible Applications D. G. Ast, a-Si H FET-Addressed LCD Panel S. Kaneko, Solid-State Image Sensor M. Matsumura, Charge-Coupled Devices M. A. Bosch, Optical Recording A. D Amico and G. Fortmato, Ambient Sensors H. Kukimoto, Amorphous Light-Emitting Devices R. J. Phelan, Jr., Fast Detectors and Modulators J. I. Pankove, Hybrid Structures... 

Waterside problems that lead to decreases in efficiency and material deterioration can be caused by a variety of mechanisms, such as electrochemical corrosion and deposition of foulants. These problems can be exacerbated by low flow, poor operational practice, process contamination, or specific stresses. It is also important to try to determine cause and effect relationships in order to provide a logical and practical water treatment solution. Such a solution will usually involve some form of cleaning, plus a combined engineering and chemical action plan. Inspection may be made easier by the use of a Boroscope or similar optical/video recording device. The color, texture, and quantity of all deposits should be noted, measurements of pits taken, and microbiological contaminants analyzed. It may be useful to conduct biocide efficiency tests on bacterial slimes. The period when a heat exchanger is open for inspection may be an opportune time for the permanent installation of ports for corrosion-monitoring probes. 

The last volume of this miniseries, 21, Part D, covers device applications, including solar cells, electrophotography, image pickup tubes, field effect transistors (FETs) and FET-addressed liquid crystal display panels, solid state image sensors, charge-coupled devices, optical recording, visible light... 

IE. Electrical Methods of Analysis. Among the various electrical properties which have been used for analysis and for which measuring apparatus may be directly incorporated in the reaction chamber are the dielectric constant the electrical conductance the pH by using glass, calomel, or H electrodes the redox potential and, in the case of gas reactions, the thermal conductivity. These properties are easily measured and lend themselves, as do the optical methods, to automatic recording devices. However, they also must be used only after careful calibratiomand do not give better than 1 per cent accuracy without unusual attention. 

Optical memory devices such as compact disks (CDs) and digital versatile disks (DVDs) are becoming essential items of audio and visual media as well as of external computer memory media. In these devices, a laser beamis used to record and read information. Because the laser spot can be focused to within a 1 fxm scale, optical memory can access higher density and capacity than conventional magnetic memories can. 

JL olymers are increasingly being used in a wide variety of applications in electronics and photonics, most of which use polymers in their traditional role as engineering materials (e.g., circuit boards, molded products, wire and cable insulation, encapsulants, and adhesives). In addition, many other unique applications require material properties that only polymers can provide. Examples include resist materials for the lithographic fabrication of integrated circuits (1C) and polymers for optical recording. These types of applications may be considered passive in the sense that the polymer does not play an active role in the operation of the device or circuit. Rather, it serves some other function such as mechanical support, electrical insulation, or in the case of resists, some intermediate function in the fabrication of the device. 

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